Walker S, MacNeil S, Tomlinson S
Br J Hosp Med. 1984 Oct;32(4):198-201.
The two best-defined intracellular signalling systems are cAMP and calcium. It is clear that the actions of cAMP depend on its interaction with an enzyme--cAMP-dependent protein kinase. One of the major developments in recent years has been the recognition that many of the intracellular actions of calcium occur through its binding to and activation of calmodulin.
两个定义最明确的细胞内信号系统是环磷酸腺苷（cAMP）和钙。很明显，cAMP的作用取决于它与一种酶——cAMP依赖性蛋白激酶的相互作用。近年来的一个主要进展是认识到钙的许多细胞内作用是通过它与钙调蛋白的结合及激活而发生的。
